JP5152740B2 - Antibacterial complex and method for producing the same - Google Patents

Description

  The present invention relates to an antibacterial complex, and more particularly to an antibacterial complex comprising a polyamide support and a porous membrane containing chitosan, and a method for producing the same.

  Chitosan is a de-N-acetylated product of chitin obtained from crustacean shells such as crabs and shrimps, insect epidermis, and bacterial cell walls such as mushrooms. In recent years, attention has been paid to the antibacterial action of chitosan, and attempts have been made to develop high-value-added products that exhibit antibacterial action by processing synthetic fibers such as polyamide fibers using chitosan.

  As such an attempt, for example, a method is known in which chitosan is adhered to the fiber surface by spraying a chitosan mixture on the fiber and heat-treating (Patent Document 1). Also known is a method for obtaining antibacterial fibers that are resistant to washing by treating synthetic fibers such as polyamide fibers with an aqueous solution containing chitosan salt while using tannic acid or using graft technology (patent) References 2 and 3). However, when chitosan is applied to a fiber by such a method, the performance as an antibacterial fiber is not always sufficient because chitosan is easily removed from the fiber.

  Patent Document 4 discloses an invention related to a stocking using at least a part of an antibacterial nylon yarn obtained by adding and mixing an antibacterial material and then spinning it. Also known is a method for hydrophilizing a polyamide-based synthetic fiber, characterized in that the fiber is treated with an aqueous acid solution, then treated with an aqueous crosslinking reagent solution having a plurality of glycidyl ether groups, and further treated with an aqueous polysaccharide solution ( Patent Document 5). However, when chitosan is applied to the fiber by such a method, the chitosan is buried inside the fiber and hardly appears on the surface, so that sufficient antibacterial properties cannot be expressed. In the latter case, there is also a problem that the strength of the fiber further decreases.

  Furthermore, in Patent Document 6, a woven fabric made of natural fibers as a holding layer is bonded to the polyolefin surface of a film formed by laminating unstretched polyolefin on a base material layer made of polyester or nylon to form a laminated sheet, 1 or 2 types selected from the group consisting of A) glucomannan, B) pullulan, carrageenan or chitosan and C) polyhydric alcohol, sugar alcohol, monosaccharide, disaccharide and oligosaccharide. It is disclosed that a viscous liquid containing the above is impregnated and dried to obtain a wound dressing. However, the covering material obtained in this way has a disadvantage that the substance in the holding layer is simply supported by adsorption, and the substance is easily detached when the covering material is used. Further, the laminated sheet adhered was poor in stretchability.

Japanese Patent Laid-Open No. 7-242772 JP-A-8-218276 JP-A-8-284066 JP-A-5-302203 JP-A-9-296369 JP 2004-248949 A

  An object of the present invention is to provide an antibacterial composite having an advanced and long-lasting antibacterial action and excellent mechanical properties such as tensile strength.

  The present invention relates to an antibacterial composite comprising a polyamide support and a porous membrane containing chitosan, and a method for producing the same.

  In the present invention, the polyamide that can be used as the base of the polyamide support is an arbitrary polymer formed by combining one or more acid amide repeating units, and is not particularly limited. Such polyamides are generally used as a base for polyamide supports such as so-called nylon (registered trademark), which is a polyamide containing an aliphatic skeleton, and aramid, which is a wholly aromatic polyamide composed only of an aromatic skeleton. Any polyamide known to be obtained is included. Examples of nylon include nylon 6, nylon 11, and nylon 12 obtained by amino acid polycondensation reaction, as well as nylon 66, nylon 610, nylon 612, nylon 6T, nylon 6I, nylon 9T, and nylon M5T. Copolymer nylon is included. Representative examples of the aramid include Kevlar (registered trademark) and Nomex (registered trademark). Such polyamides may be used alone or in combination of two or more.

  In the present invention, the support based on polyamide may have any shape, and is arbitrarily selected according to the application to which antibacterial properties should be imparted. For example, textiles such as fibers themselves, knitted fabrics, woven fabrics, and nonwoven fabrics, films, sheets, foams, and the like are typical examples of suitable supports. Among these, nylon fibers or nylon films are suitable as the polyamide support of the present invention. In particular, when the antibacterial composite of the present invention is constituted using a fiber as a support, a fiber having a diameter of 6 μm to 5 mm can be advantageously used depending on the end use and purpose. As an end use in this case, the antibacterial complex of the present invention can be advantageously used as at least a part of ultrafine fibers constituting a stocking or at least a part of ultrathin fibers constituting a toothbrush.

  In the present invention, chitosan that can be used to be contained in the porous membrane generally refers to chitin obtained from crustacean shells such as crabs and shrimps, insect epidermis, skeletons such as squid, and bacterial cell walls such as mushrooms. De-N-acetylated product. That is, when chitin is treated with an alkali to remove most of the acetyl group, it is converted into chitosan having a D-glucosamine unit as a main constituent. The chitosan in the present invention is preferably soluble in an acidic aqueous solution.

  In the present invention, the term “chitosan” includes chitosan oligomers. The chitosan in the present invention preferably has a weight average molecular weight in the range of 1,000 to 1,000,000. If the weight average molecular weight of chitosan is too low, water solubility becomes high and it easily dissolves in water or hot water. As a result, the amount of chitosan contained in the porous membrane decreases, so the target antibacterial action is sufficient May not be obtained. In particular, when finely powdered chitosan is used, the weight average molecular weight is more preferably 2000 or more, further preferably 5000 or more, and particularly preferably 9000 or more.

  On the other hand, if the weight average molecular weight of chitosan is too high, there may be inconveniences such as it takes too much time to be hydrolyzed by animal body fluids or the like from about 9000 to about 10,000 exhibiting antibacterial properties. Therefore, the weight average molecular weight of chitosan is more preferably 700,000 or less, further preferably 500,000 or less, still more preferably 300,000 or less, particularly preferably 100,000 or less, and most preferably 50,000 or less.

  In some embodiments of the invention, it is also preferred that the chitosan is an oligomer. In this case, the weight average molecular weight of chitosan is preferably 1000 or more, more preferably 5000 or more, preferably 10,000 or less, and more preferably 9000 or less.

  In the present invention, by using chitosan having a weight average molecular weight within the above range, a desired antibacterial action can be obtained, and it can be easily applied to a support by dissolving or suspending chitosan in a polyamide solution. It becomes.

  The antibacterial complex according to the present invention comprises the above polyamide support and a porous membrane containing chitosan. That is, it is important that the above-mentioned chitosan is contained in the porous membrane, and it is particularly preferable that at least a part of the chitosan is exposed on the surface of the porous membrane as described in detail below. In the present invention, since chitosan is supported on the porous membrane, it is possible to impart a high level of antibacterial action to the antibacterial complex, and the chitosan does not fall off during the production process and use process of the antibacterial complex. , Can maintain a high antibacterial action.

  In the present invention, a polymer is usually used as the base of the porous membrane. Such a polymer is preferably selected from the polyamides used as the base of the polyamide support in the present invention. As the base of the porous membrane, the same material as the polyamide used as the base of the polyamide support in the present invention or a different material may be used, but the same or compositionally similar material may be used. From the viewpoint of affinity.

  In order to develop a high antibacterial action, it is preferable that at least a part of chitosan is exposed on the surface of the porous membrane. The exposure amount of chitosan in the antibacterial complex of the present invention can be measured by chitosan hydrolysis with an enzyme described later. The exposure amount of chitosan thus measured is preferably in the range of 30 to 99% by weight based on the weight of the porous membrane from the viewpoint of efficiently developing a high antibacterial action. The larger the exposure amount, the better the antibacterial property, but if it is too large, the chitosan may fall off during the production and use of the antibacterial complex. Therefore, a more preferable exposure amount is 97% by weight or less, more preferably 95% by weight or less based on the weight of the porous membrane. On the other hand, when the exposure amount is too small, sufficient antibacterial action is not exhibited. Therefore, a more preferable exposure amount is 30% by weight or more, more preferably 80% by weight or more based on the weight of the porous membrane.

  Moreover, it is preferable that the antimicrobial complex of this invention exists in the range whose calcium metal amount contained in the film | membrane surface measured by the chelate titration method mentioned later is 0-10 ppm.

  The antimicrobial complex of the present invention may contain chitosan in any proportion. In order to impart an advanced and long-lasting antibacterial action, chitosan is preferably 0.1 parts by weight or more, more preferably 1 part by weight or more, and further preferably 5 parts by weight or more with respect to 100 parts by weight of the composite. Included in the ratio. Further, from the viewpoint of easily forming a desired porous membrane as described above and the cost, chitosan is preferably 60 parts by weight or less, more preferably 55 parts by weight or less, with respect to 100 parts by weight of the composite. More preferably, it is contained in a proportion of 40 parts by weight or less.

Next, the antibacterial complex of the present invention described above, and a method for producing the antibacterial complex of the present invention in a preferred embodiment will be described.
The method for producing the antibacterial complex of the present invention comprises:
A step of suspending or dissolving chitosan or polyamide and chitosan in a polyamide solvent to obtain a mixed solution;
Applying the mixture to a polyamide support and then treating the resulting coating with hot water to obtain a composite having a porous thin film;
A step of drying the obtained composite,
Comprising.

  In the present invention, the polyamide solvent refers to a solvent capable of dissolving the polyamide, and a solvent capable of dissolving or suspending the chitosan is preferably used. Specific examples of such solvents include saturated methanol solution or saturated ethanol solution of the following solutions: calcium chloride dihydrate, lithium chloride, dimethylformamide / lithium chloride solution, dimethylformamide / odor. Lithium fluoride solution, dimethylformamide / calcium chloride solution, dimethylformamide / calcium bromide solution, dimethyl sulfoxide / lithium chloride solution, dimethyl sulfoxide / lithium bromide solution, dimethyl sulfoxide / calcium chloride solution, dimethyl sulfoxide / calcium bromide solution, Concentrated formic acid, dichloroacetic acid, methanesulfonic acid, concentrated sulfuric acid. Among these, saturated alcohol of calcium halide hydrate is suitable as a solvent having relatively little toxicity, and in particular, calcium chloride dihydrate saturated methanol solution and calcium chloride dihydrate saturated ethanol solution are It can be particularly preferably used in the invention.

  The order in which chitosan or polyamide and chitosan are dissolved or suspended in the solvent of polyamide is not limited. Polyamide and chitosan may be simultaneously added to the solvent and dissolved or suspended, or the respective processing solutions previously dissolved or suspended in the solvent may be mixed. The concentration of polyamide and chitosan dissolved or suspended in the solvent can be appropriately determined according to the solubility of each substance in the solvent, the suspension stability, the particle size of the chitosan powder, and the like. The polyamide concentration in the mixed solution is usually 0 w / v% or more, preferably 0.2 w / v% or more, more preferably 0.5 w / v% or more, and usually 20 w / v% or less, preferably 5 w. / V% or less, more preferably 5 w / v% or less. On the other hand, the chitosan concentration is usually 0.001 w / v% or more, preferably 0.1 w / v% or more, more preferably 0.2 w / v% or more, further preferably 0.5 w / v% or more, and usually It is 20 w / v% or less, preferably 10 w / v% or less, more preferably 5 w / v% or less, and still more preferably 3 w / v% or less. As described above, chitosan having various weight average molecular weights can be used. For example, when chitosan fine powder having a large weight average molecular weight is used, it is usually within a range of 0.01 w / v% to 20 w / v%. Even when a chitosan oligomer having a low weight average molecular weight is used as a suspension having a concentration, it is advantageous to obtain a mixed solution as a solution having a concentration usually within a range of 0.01 w / v% to 20 w / v%. It can be.

  In the present invention, the suspension or dissolution of chitosan or polyamide and chitosan in a polyamide solvent is usually performed at room temperature or higher, preferably 35 ° C to 60 ° C, more preferably 40 ° C to 50 ° C.

Next, after apply | coating the obtained liquid mixture to a polyamide support body, the obtained coating material is processed with a hot water, and the composite_body | complex which has a porous thin film is obtained.
As a means for applying to the surface of the support, a method of applying a liquid mixture to the surface of the support and spreading it thin may be employed, or a method of pulverizing and lifting the support in the liquid mixture may be employed. In order to facilitate the application, a method in which the support surface to be applied is preliminarily immersed in the above-described solvent to form a support surface in a gel state can be advantageously employed.

  When performing the coating, the temperature of the mixed solution is usually room temperature or higher, preferably about 35 ° C to 60 ° C, more preferably 40 ° C to 50 ° C. The coating treatment time is not particularly limited, but is usually 1 minute to 6 hours, preferably 5 minutes to 5 hours, more preferably 10 minutes to 1 hour.

  For example, when a chitosan-polyamide mixed solution obtained using calcium chloride dihydrate saturated methanol as a solvent is applied, chitosan fine particles can be suitably dispersed in the obtained applied product.

  Next, usually, after removing a part of the mixed solution and drying, the coated material is treated with hot water. By this hot water treatment, the solvent containing the calcium salt is rapidly removed from the coated material, and as a result, a porous film is formed on the surface of the support. Here, it is preferable that the hot water to be used has a temperature of 50 ° C to 100 ° C, and a more preferable temperature is 60 ° C to 80 ° C.

  Hereinafter, the effectiveness of the present invention will be described with reference to examples, but the present invention is not limited thereto. In addition, the evaluation method of the physical property in the following examples is as follows.

1. Confirmation of chitosan exposure on sample surface The samples obtained in each experimental example were qualitatively analyzed by ninhydrin test. That is, a ninhydrin 0.1% (v / v) isopropyl alcohol solution was sprayed onto an appropriate amount of each sample and dried at 80 ° C. for 1 hour. It was judged that chitosan had adhered (exposed) to the sample surface when a purple color change was confirmed in each sample after drying.

2. Chitosan exposure amount The exposure amount of chitosan exposed on the surface of the sample obtained in each experimental example was analyzed using chitosanase (manufactured by Wako Pure Chemical Industries, Ltd.) which is a chitosan degrading enzyme. That is, chitosan was hydrolyzed with chitosanase, and the amount of chitosan exposure was measured from the weight loss before and after decomposition. Details of the analysis method are shown below.
The pH was adjusted to 5 by adding 4% (w / v) sodium hydroxide aqueous solution to 100 mL of 1% (v / v) acetic acid aqueous solution of pH 3. 0.354g of each sample was put in it. The solution containing the sample was slowly stirred at room temperature for 2 hours, then 0.004 g of chitosanase was added and stirred to hydrolyze. After one week, a sample was taken out from the acetic acid aqueous solution and washed with distilled water. The weight of the sample after drying was measured, and the amount of chitosan exposed was determined from the weight loss before and after hydrolysis.

3. Antibacterial test The culture medium and sample which added the microbe were put into the test tube, and the shaking culture for 1 hour was performed. The determination was made based on the fact that the sterilization rate calculated from the number of bacteria when the sample was not added and the number of bacteria when the sample was added was 26% or more. Viable count was performed by a spiral plate method using an agar medium.

As a sample preparation, 0.04 g was weighed from each specimen, put into a test tube, and autoclaved at 121 ° C. for 15 minutes.
As a medium preparation, the test strain was planted on an agar medium and cultured at 35 ° C. for 20 hours. This was used as a dangerous strain. The test strain was suspended in a sterilized ordinary broth and prepared with a turbidity so as to obtain a certain amount of bacteria. A solution obtained by diluting this bacterial solution to 1/15000 with a phosphate buffer was used as a test medium.
As a shaking culture, 4 ml each of test medium was added to a test tube sterilized with a sample, and the shaking culture was performed in a 35 ° C. incubator at 160 rpm for 1 hour.
In order to measure the number of viable bacteria in the test medium before and after shaking culture, a standard agar medium was used and a spiral plate method was performed as the viable cell count.
The strains used in the tests were Staphelococcus aureus (NBRC13276) (hereinafter Sa) and Klebsiellapneumoniae (NBRC14940) (hereinafter Kp).
There were two types of media used in the test: standard agar medium (Merck Co., Ltd.) and ordinary bouillon (Merck Co., Ltd.).

The sterilization rate was calculated as follows.
Bactericidal rate (%): ((A−B) / A) × 100
A: Viable count before shaking
B: Viable count after shaking

Judgment conditions for evaluation effectiveness were as follows.
(1) Effective if the sterilization rate Z of the unprocessed sample (blank) is Z <30%.
(2) When the sterilization rate Y of the processed sample is (YZ)> 26%, the antibacterial property is recognized.

4). Tensile strength Tensile strength was measured using an Instron universal material testing machine under the following conditions.
(1) Tie both ends of the fiber to a rod with a diameter of about 2 mm.
(2) Clamp the rod to which the fibers are tied in (1) to the fixed part of the measurement probe.
(3) Tensile strength was determined from the load when the material was pulled and torn at a tensile rate of 10 mm / min.

(Preparation Example 1: Preparation of calcium solvent)
1700 g of calcium chloride dihydrate was added to 2 L of methanol, and the mixture was stirred at 40-50 ° C. for about 4 hours, and then allowed to stand at room temperature for about 15 hours. Next, the insoluble part was removed by filtration using a filter cloth, and the obtained solution was used as a calcium solvent.

(Preparation Example 2: Preparation of nylon 12 solution)
10 g of nylon 12 was added to 100 mL of the calcium solvent obtained in Preparation Example 1 and dissolved at 40 to 50 ° C. to obtain a 10 w / v% nylon 12 solution.

(Preparation Example 3: Preparation of chitosan-nylon suspension A)
A solution in which 50 mL of a calcium solvent is added to 50 mL of the nylon 12 solution obtained in Preparation Example 2 (5 w / v% nylon solution) and 2 g of chitosan powder (product number: Flownack C, Kyowa Technos Co., Ltd.) is crushed in a mortar Were mixed to obtain chitosan-nylon suspension A.

(Preparation Example 4: Preparation of chitosan-nylon suspension B)
Chitosan powder (product number; Flownack C, Kyowa Technos Co., Ltd.) is dissolved in glacial acetic acid, added with hydrogen peroxide solution to lower the molecular weight, neutralized with aqueous sodium hydroxide solution, neutralized, and concentrated It was precipitated with acetone, washed with methanol, and dried at room temperature to obtain a chitosan oligomer. 0.2 g of the obtained chitosan oligomer was mixed with a solution obtained by adding 40 mL of calcium solvent to 25 mL of the nylon 12 solution obtained in Preparation Example 2 to obtain a chitosan-nylon suspension B.

(Preparation Example 5: Preparation of fluorescent nylon solution)
To 100 mL of the calcium solvent obtained in Preparation Example 1, 2.0 g of fluorescent nylon tex was added and dissolved at 40 to 50 ° C. to obtain a fluorescent nylon solution.

(Preparation Example 6: Preparation of chitosan-nylon suspension C)
To 100 mL of the fluorescent nylon solution obtained in Preparation Example 5, 2.0 g of 9% (w / v water) chitosan hydrogel was mixed to obtain a chitosan-nylon suspension C.

(Preparation Example 7: Preparation of nylon 6.6 solution)
2.0 g of nylon 6.6 (UBE2020, manufactured by Ube Industries, Ltd.) is added to 200 mL of the calcium solvent obtained in Preparation Example 1 and dissolved at 40 to 50 ° C. to obtain a 1 w / v% nylon 6.6 solution. Got.

(Preparation Example 8: Preparation of chitosan-nylon suspension D)
A chitosan-nylon suspension D was obtained in the same manner as in Preparation Example 3, except that 80 mL of the nylon 6.6 solution obtained in Preparation Example 7 was used.

(Preparation Example 9: Preparation of fluorescently stained chitosan)
FITC in which 5 mL of fluorescein-5-isothiocyanate (FITC) (manufactured by Merk KGaA) was dissolved in 50 mL of ethanol in a suspension obtained by adding 50 mL of distilled water to 22.8 g of 9% (w / v water) chitosan hydrogel. 1 mL of the solution was added with a female pipette and stirred at 500 rpm for 30 minutes. After the stirring was stopped, the mixture was allowed to stand overnight. This was filtered, washed with distilled water, acetone, and ethanol in that order, dried, and then pulverized with a mortar to obtain finely powdered fluorescently stained chitosan.

(Preparation Example 10: Preparation of fluorescent chitosan-nylon suspension)
The fluorescently stained chitosan obtained in Preparation Example 9 was mixed with 20 mL of the nylon 6.6 solution obtained in Preparation Example 7 to obtain a fluorescent chitosan-nylon suspension.

Example 1
About 75 cm of nylon 6.10 fiber (diameter 200 μm) was immersed in the calcium solvent obtained in Preparation Example 30 for 30 minutes as a pretreatment, and then in the chitosan-nylon suspension A obtained in Preparation Example 3 above. It was gradually put in and pulled out over about 30 seconds. Next, after the drawn fiber was dried at room temperature for 1 to 4 hours, it was immersed in warm water at 70 to 90 ° C. for 10 minutes for desalting (and desolvation), and dried at room temperature. The obtained nylon fiber was observed with a scanning electron microscope (SEM). As a result, it was found that chitosan was deposited on the surface of the nylon fiber by the chitosan-nylon suspension A and was coated in a porous film state.

(Example 2)
The same procedure as in Example 1 was performed except that the chitosan-nylon suspension B obtained in Preparation Example 4 was used instead of the chitosan-nylon suspension A. The obtained nylon fiber was observed with a scanning electron microscope (SEM). As a result, it was found that chitosan was deposited on the surface of nylon by chitosan-nylon suspension B and coated in the state of a porous film.

(Example 3)
Nylon 6,6 fibers (diameter 8 μm, weight 0.226 g) are passed through an L-shaped tube containing 30 ml of the chitosan-nylon preparation solution A obtained in Preparation Example 3 and adjusted so that the immersion time is about 1 second. And wound up with a winder. The wound fiber was dried at room temperature for 30 minutes. Thereafter, the same procedure as in Example 1 was performed. The obtained nylon fiber was observed with a scanning electron microscope (SEM). As a result, it was found that chitosan was deposited on the surface of nylon by chitosan-nylon suspension A and was coated in the state of a porous film.

(Analysis of chitosan exposure)
The exposed amount of chitosan exposed on the fiber surface of nylon 6.6 obtained in Example 3 was analyzed using chitosanase which is a degrading enzyme of chitosan. That is, the pH was adjusted to 5 by adding 4% (w / v) sodium hydroxide aqueous solution to 100 mL of 1% (v / v) acetic acid aqueous solution of pH 3. 0.354 g of the nylon 6.6 fiber obtained in Example 3 was put therein. The solution containing the fibers was slowly stirred at room temperature for 2 hours, then 0.004 g of chitosanase was added and stirred to hydrolyze. After one week, the fiber was taken out from the acetic acid aqueous solution and washed with distilled water. The weight of the fiber after drying was 0.287 g. From the weight loss before and after hydrolysis, it was found that 0.067 g of chitosan was exposed. Since the chitosan content calculated from the film thickness of 1 μm and the composition ratio determined by SEM observation was 0.071 g, it was found that about 95% of chitosan was exposed.

(Antimicrobial test results)
An antibacterial test was conducted using the nylon 6.6 fiber (coated sample) coated with chitosan-nylon obtained in Example 3 and the nylon 6.6 fiber (blank) not subjected to coating treatment as specimens. The results of viable cell count measurement are shown in Table 1.

  As a result of obtaining the sterilization rate of the processed sample (coat sample), YZ was 68.5% for Sa and 58.9% for Kp, exceeding the standard value of 26%. It was.

Example 4
The same procedure as in Example 3 was performed except that the chitosan-nylon suspension B obtained in Preparation Example 4 was used instead of the chitosan-nylon suspension A. The obtained nylon was observed with a scanning electron microscope (SEM). As a result, it was found that chitosan was deposited on the surface of nylon by chitosan-nylon suspension B and coated in the state of a porous film.

(Example 5)
The same procedure as in Example 1 was performed except that chitosan-nylon suspension C was used instead of chitosan-nylon suspension A. As a result of observing the obtained nylon with a fluorescence microscope, green fluorescence was confirmed on the entire nylon fiber surface when blue light was applied. Similarly to the above, no fluorescence was emitted even when blue light was applied to nylon fibers not coated with chitosan / nylon.

(Example 6) Evaluation of the amount of calcium metal contained in the membrane The amount of calcium metal contained in the membrane was measured by chelate titration after producing chitosan / nylon coated fibers as follows. Calcium metal is usually present in the film as its chloride, CaCl ₂ . Therefore, the amount of calcium metal is an index indicating the amount of residual chlorine.

  First, nylon 6 fibers (diameter 143 μm, length 30 m (0.578 g)) were passed through an L-shaped tube containing about 30 ml of the chitosan-nylon suspension A obtained in Preparation Example 3 and treated in the same manner as in Example 3. The chitosan / nylon coated fiber was prepared. The weight of the obtained fiber was 0.594 g. Next, the fiber was incinerated at 800 ° C. in the air with a platinum crucible. The ash fired product was eluted with dilute sulfuric acid, and the amount of calcium was titrated with EDTA standard solution using Eriochrome Black T as an indicator. As a result, it was found that 3 ppm of calcium was present.

(Example 7) Evaluation of tensile strength Tensile strength was measured in order to examine whether or not the strength of the fiber was lowered by chitosan / nylon coating. As described above, an Instron universal material testing machine was used for the measurement.
Measurement was performed under the following conditions using the uncoated fiber (blank) and the chitosan-nylon coated fiber prepared in Example 6 as an evaluation sample.
First, both ends of the fiber were tied to a rod having a diameter of about 2 mm. Next, the rod to which the fibers were bound was clamped to the fixed part of the measurement probe. Next, the tensile strength was calculated | required from the load (proof load) at the time of pulling at 10 mm / min.

As a result of measuring the blank five times, the average load resistance was 517.0 g, the standard deviation was 52.6, and the tensile strength was 3.28 N / mm ² . On the other hand, in the coated fiber, the load resistance was 459.1 g and 612.1 g, respectively, as a result of two measurements. The tensile strength determined from the average value 535.6 g was 3.40 N / mm ² . From the above results, it was found that the fiber strength was not decreased by the chitosan-nylon coating.

(Example 8)
Instead of the chitosan-nylon suspension A, the same procedure as in Example 1 was carried out except that the chitosan-nylon suspension D obtained in Preparation Example 8 was used. The obtained nylon fiber was observed with a scanning electron microscope (SEM). As a result, it was found that chitosan was deposited on the surface of nylon by chitosan-nylon suspension D and was coated in a porous film state.

Example 9
About 30 cm of nylon 6 fiber was immersed in the fluorescent chitosan-nylon suspension obtained in Preparation Example 10 for 10 minutes, dried for 1 to 4 hours, and then immersed in warm water at 70 to 90 ° C. for 10 minutes for desalting ( And desolvation) and drying at room temperature. The obtained sample was irradiated with excitation light having a wavelength band of about 405 to 490 nm, and the generated fluorescence was observed with a fluorescence microscope through a filter that transmits about 540 nm or more. As a result, it was found that fluorescence was observed on the entire surface of the nylon fiber, and the distribution of chitosan in the coating film could be optically observed.
Similarly, in the nylon 6 fiber coated with the chitosan-nylon suspension D which was not subjected to the fluorescent staining obtained in Preparation Example 8, no fluorescence could be confirmed.

Claims (11)

  An antibacterial composite comprising a polyamide support and a porous membrane containing chitosan.   The antibacterial complex according to claim 1, wherein at least a part of chitosan is exposed on the surface of the porous membrane.   The antibacterial complex according to claim 2, wherein the amount of chitosan exposed is in the range of 30 to 99% by weight based on the weight of the porous membrane.   The antibacterial complex according to any one of claims 1 to 3, wherein the amount of calcium metal contained in the porous membrane as measured by chelate titration is in the range of 0 to 10 ppm.   The antimicrobial complex according to any one of claims 1 to 4, wherein chitosan has a weight average molecular weight in the range of 1000 to 1000000.   The antibacterial complex according to any one of claims 1 to 4, wherein chitosan is an oligomer having a weight average molecular weight in the range of 5000 to 10,000.   The antimicrobial composite according to any one of claims 1 to 6, wherein the polyamide support is a nylon fiber.   The antimicrobial composite according to any one of claims 1 to 6, wherein the polyamide support is a nylon film. It is a manufacturing method of the antibacterial complex in any one of Claims 1-8,
A step of suspending or dissolving chitosan or polyamide and chitosan in a polyamide solvent to obtain a mixed solution;
Applying the mixture to a polyamide support and then treating the resulting coating with hot water to obtain a composite having a porous thin film;
A step of drying the obtained composite,
Including a method.   10. The method according to claim 9, comprising the step of presoaking and swelling the polyamide support in the solvent prior to application.   The method of claim 9 or 10, wherein the polyamide solvent is a saturated alcohol of calcium halide hydrate.